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Mooney M20 performance and specifications

Mooney has
changed ownership several times over the
years. It even became a French owned company
for a while. The design of the M20 is one of
the most outstanding aviation achievements.
The tail is to say the least unusual.
However, it remains in the airflow at
extreme attitudes and does not slow the
thing down at all. What is even more unusual
is that the entire tail hinges to enable
trim changes. Unlike most modern aircraft,
the fuselage has a moly steel space frame
around the passenger compartment and this
give vastly improved occupant survivability
in the unfortunate event of an accident.
Many feel that the cockpit is cramped. This
is an optical illusion, as the internal
dimensions are very similar to a Bonanza.
Control harmony takes an hour to get used
to, and after that, most pilots fall in
love. After closing the doors a short time
ago, Mooney is back again making these fine
airplanes and the business seems to be going
from strength to strength. The aircraft is a
perfect long distance cruiser and is not all
that bad air racing either! If all of this
seems a tad biased, perhaps it is. I owned a
Mooney for some time and love them to this
day! (ed.)

first Mk20

The first M20
was built in 1955 and was Al Mooney’s
twentieth aircraft design. Dubbed the M20A,
this all-wooden wing aircraft was in
production until 1961 when the all-metal
M20B was introduced. This was superseded by
the M20C Mk 21 in 1962. In 1964 an
additional model became available — the M20E
Super 21 with a 200-hp injected Lycoming
giving a maximum cruise of 187 mph. Mooney’s
competition at this time was Piper’s 250-hp
Comanche.

Back then, Air
Facts magazine set up a race between the two
rivals. Conducted at low-level with
throttles wide open, the Mooney outran the
Comanche. By 1965, sales at Mooney were
booming, selling almost 700 aircraft that
year, with theM20F Executive with stretched
fuselage offered a year later in 1966. The
last of theM20Cs was built in 1978, a year
after the popular 200-hp M20J was introduced
— known as the 201 because the cruise speed
was 201 mph. The M20K 231/252 first appeared
in 1979 and differed from the 201 in that it
had a Continental 210-hp.

In 1988 Mooney
teamed up with Porsche and produced
forty-one 217-hpPorsche engined aircraft,
the M20L — two of which are flying in
Australia. The incredibly quick, big-block
Mooneys began rolling off the line in 1988
with the 220-knot, 270-hpM20M Bravo,
followed by the 280-hp M20ROvation in 1994.
Mooney’s newest model is the 244-hp M20S
Eagle. While the latest M20 Mooneys feature
more power, speed, state-of-the-art avionics
and luxuriously appointed interiors, the
entire M20series have an almost identical
airframe and many other features not found
on other light aircraft. Without a doubt,
the most distinguishing feature is the
unique Mooney tail design with its forward
sloping trailing-edge and vertical
leading-edge.

The theory is
that the tail design positions the rudder
directly in-line with the airflow when at
slow speeds and high nose attitudes. This
makes the rudder more effective just when
you really need it, such as when landing or
approaching a stall. Probably a lesser known
fact is that the Mooney pitch trim control
moves the entire empennage rather than using
drag inducing trim tabs.

The flush
riveted laminar flow Mooney wing is also a
unique design in that it is very strong,
one-piece and has a single spar from wingtip
to wingtip. Apparently the fuselage can be
removed and the wing rolled around on the
wheels. The flaps stretch out over nearly
two-thirds of the wing, while the ailerons
are short and wide and run right to the tip
of the wing — a combination designed to give
better control at slow speeds.

Attached to the
wing is an equally strong fuselage. Rather
than being the typical monocoque
construction, Mooneys feature a welded steel
tubular frame wrapped with non-structural
aluminium as the foundation for the forward
fuselage. The steel frame also acts as a
roll cage around the occupants. Not
surprisingly, there has never been a
structural AD on a metal Mooney airframe and
only one mid-air break up — that unfortunate
person entered a tornado-ridden
thunderstorm.

All M20 series
Mooneys share the same load limitations of
+3.8g and -1.5g.The trailing link tricycle
gear has a rudder-pedal-operated steerable
nose wheel and toe-operated brakes. Rather
than conventional oleo legs, Mooneys utilise
low maintenance rubber discs to absorb shock
from taxiing and landing. Anyone who has
woken up in the morning at a remote strip to
find a collapsed oleo leg will appreciate
this system.

Al Mooney was
so intent on reducing drag that even the
step on the M20C is retractable. Getting
into the low, left seat of a Mooney does
require some mild gymnastics compared with
the high chair of a Cessna. Once seated with
legs stretched outwards, the Mooney is
comfortable and the cabin width, contrary to
popular opinion, is almost exactly the same
as a Beech, Piper or Cessna. Mooney has
reduced the fuselage cross sectional area
and therefore reduced drag by lowering the
area above the pilot’s head and curving in
the side windows above the shoulder.

The Mooney is
the ultimate cross-country machine. The M20C
burns around 35 litres per hour at 75
percent power, giving it a maximum endurance
of 5 hours. Don’t forget that at Mooney
speeds, that equates to a long way on a tank
of gas.

Normal take-off
speed is 60 knots and a climb rate of 800
ft/min can be expected at 105 knots. With a
constant speed propeller, the tightly
enclosed O-360 A1D Lycoming develops 180hp
at 2,700 rpm and requires the use of cowl
flaps during the climb.

Electrical
failure in earlier models presents no major
dramas. Up until 1968, all Mooneys had a
bullet-proof manual gear retraction system.
Hinged from the floor, the long gear handle,
or Johnson Bar, locks forward into the
bottom of the instrument panel for the down
position. To retract, the thumb button is
depressed while sliding the locking
mechanism downwards and the handle is pulled
to floor between the seats.

The entire
retraction of all three wheels seems almost
instantaneous and is effortless if done
before too much speed is gained. Flaps are
extended hydraulically through a manual
handle located next to the gear. Full flap
is obtained with four complete pumps, and
the flaps will retract automatically. Mooney
introduced electrically operated landing
gear and flaps as standard in 1969, however,
the manual gear is so popular there is no
price difference between electric and manual
gear when purchasing an early Mooney. The
dual flight controls feel heavier than other
similar aircraft due to having push-pull
tubes rather than cables, and serve as a
stable cross-country and instrument
platform.

The rudder is
the lightest control of all three axes and
is also the least powerful, although 15-knot
cross wind landings are possible.
Anticipation and generous use of trim and
rudder is required when applying full power
in a go-around or missed approach situation
as the pitch up is significant.

Until 1977,
standard Mooney equipment included an
automatic wing leveller known as the
Positive Control or PC system. Pneumatically
operated, the PC system senses both roll and
yaw in the turn coordinator, which meters
vacuum to cylinders attached to the control
tubes. Slowing the slippery Mooney down
re-quires forward planning.

The M20C has a
maximum gear retraction speed of 105 knots
and flap speed of 89 knots, so it requires
some thought when descending at 160 knots.
Late model Mooneys with cruise speeds of
over200 knots are equipped with pop-up speed
brakes on the wings, a modification fitted
to many earlier models. The manual gear
system is easily extended if the maximum
extension speed is adhered to. It seems hard
to imagine how one could ever forget to
lower the wheels on a Mooney as it is such a
vital drag inducing ingredient to getting
the speed under control. The Mooney has a
mild stalling behaviour typical of many
light aircraft types, however, if out of
balance it will readily drop a wing. If
severely aggravated, using full elevator and
rudder together at slow speeds, the aircraft
will stall, roll over and settle into the
initial stages of a spin which is easily
recoverable.

Mooney Eagle

Landing is no
different from landing a Cherokee so long as
you get the final approach speed down. The
majority of Mooney accidents have been the
result of the pilot not slowing enough in
the circuit and ending up with a fast final
approach speed. The recommended normal final
approach speed is 71 knots — any higher and
the aircraft will float down the entire
strip in ground effect and, if forced on,
will bounce. With a short field approach
speed of 62 knots and a stall speed in
landing configuration of 50 knots at MAUW,
the M20C is able to drop in and out of
fairly short strips. The Mooney is an
aircraft with so much capability.

It goes fast —
real fast — it’ll take four people away,
land on the local farm strip, and doesn’t
require a trust fund to run. For all its
systems, the Mooney is remarkably simple and
easy to maintain. In return for these
features, all a Mooney asks for is a pilot
who respects and knows how to handle its
high performance characteristics.

Model
Chronology

1955

M20 Mark 20

1001 to
1010

Lycoming
0-320 (150HP). Wood wing. Four place.

10

$12,500

1956

M20 Mark 20

1011 to
1061

Lycoming
0-320 (150HP). Wood wing. Four place.

51

$15,590A

1957

M20 Mark 20

1062 to
1166

Lycoming
0-320 (150HP). Wood wing. Four place.

105

$15,950A

1958

M20 Mark 20

1167 to
1200

Lycoming
O-320 (150HP). Wood wing. Four place.

34

1958

M20A Mark 20A

1201 to
1303

Lycoming
0-360-A1A (180 HP). Wood wing. Four
place.

103

$14,750 -
$17,656A

1959

M20A Mark 20A

1304 to
1534

Lycoming
0-360-A1A (180 HP). Wood wing. Four
place.

231

$15,450

1960

M20A Mark 20A

1535 to
1700

Lycoming
0-360-A1A (180 HP). Wood wing. Four
place.

165

All aircraft
manufactured to this point were of wood and
fabric construction. Aircraft after S/N 1701
were metal.